An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

• ) followed by alkylation with benzyl chloride to give the chain elongated adduct [27]. The tert-butylamide 1.24 is then dehydrated with phosphorous oxychloride at elevated temperatures to yield the nitrile derivative 1.25. Introduction of the piperidine ring is achieved by utilisation of the appropriately

• 1.84 as the nucleophile has been successfully conducted (Scheme 15) [49]. The nitrile unit is partially reduced and hydrolysed to the benzaldehyde 1.71 using Raney-Ni under transfer hydrogenation conditions in wet formic acid. A Darzens reaction between this aldehyde and ethyl chloroacetate in the

• specifically cleaves at proline residues, it is unsurprising that the members of this drug class exhibit an embedded pyrrolidine ring (or mimic) and additional decoration (a nitrile or fluorinated alkyl substituent is present in order to reach into a local lipophilic pocket). One specific structural liability

Synthesis and characterization of novel bioactive 1,2,4-oxadiazole natural product analogs bearing the N-phenylmaleimide and N-phenylsuccinimide moieties

• Catalin V. Maftei,
• Elena Fodor,
• Peter G. Jones,
• M. Heiko Franz,
• Gerhard Kelter,
• Heiner Fiebig and
• Ion Neda

Beilstein J. Org. Chem. 2013, 9, 2202–2215, doi:10.3762/bjoc.9.259

• reviewed the synthesis of 1,2,4-oxadiazoles [33]. He pointed out that two general methods dominate the practical preparation (≈95%): (a) The condensation of amidoximes with carboxylic acid derivatives. (b) The dipolar cycloaddition of nitrile oxides to nitriles. The general approach for the synthesis of

• complex as a leaving group, giving rise to the formation of the nitrile oxide. The 1,2,4-oxadiazole moiety is established by the 1,3-dipolar cycloaddition of nitrile oxide to the 4-aminobenzonitrile. However, the Lewis acid might also be involved in the formation of the heterocycle via a Lewis acid

Regioselective 1,4-trifluoromethylation of α,β-unsaturated ketones via a S-(trifluoromethyl)diphenylsulfonium salts/copper system

• Satoshi Okusu,
• Yutaka Sugita,
• Etsuko Tokunaga and
• Norio Shibata

Beilstein J. Org. Chem. 2013, 9, 2189–2193, doi:10.3762/bjoc.9.257

• aluminium-centered Lewis acid with low to moderate yields [18]. Dilman and co-workers partially overcame this problem by using highly electrophilic alkenes bearing either Meldrum’ acids [19], or two geminal nitrile groups [20]. However, direct 1,4-trifluoromethylation to conventional α,β-unsaturated ketones

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• induced domino epoxide-opening/rearrangement/cyclization cascade was accomplished by the group of Katoh (Scheme 22) [144]. The synthesis commenced with the conversion of dimethyl 2,6-dihydroxyterephthalate (172) to nitrile 173 within five consecutive steps. Hydrogenation and lactam formation of 173 gave

• installation of the isoindolinone, a seven-step sequence similar to the one described for stachyflin (156) was used (Scheme 23). The arene appendage was desymmetrized via monobromination and cross coupling with copper cyanide provided a nitrile. Hydrogenation and lactam formation under basic conditions

• diastereoselective allylic oxidation to provide (±)-nominine (225). In 2008, the same group reported the first total synthesis of (+)-nominine by introducing the desired stereochemical information to the nitrile 235 [179]. Conclusion The outlined syntheses of natural products containing the uncommon isoindole

Synthesis of enantiomerically pure (2S,3S)-5,5,5-trifluoroisoleucine and (2R,3S)-5,5,5-trifluoro-allo-isoleucine

• Holger Erdbrink,
• Elisabeth K. Nyakatura,
• Susanne Huhmann,
• Ulla I. M. Gerling,
• Dieter Lentz,
• Beate Koksch and
• Constantin Czekelius

Beilstein J. Org. Chem. 2013, 9, 2009–2014, doi:10.3762/bjoc.9.236

• sodium cyanide to afford nitrile 3. Acid hydrolysis of 3 provided the enantiomerically pure carboxylic acid (R)-4 [19], which was then coupled to the oxazolidinone via the mixed anhydride (Scheme 1). With N-acyloxazolidinone 5 in hand, the optically active fluorinated α-amino acids (L-5,5,5

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• sizes and acyclic amines underwent the α-arylation reaction to provide benzylic amines. The arylating reagents were benzonitriles substituted with an electron-withdrawing group. The nitrile group functioned as the leaving group. In some classes of five-membered heteroaromatics, a chloride was capable of

• replacing the nitrile group as the leaving group. The authors proposed a mechanistic pathway that is initiated by oxidative quenching of the photoexcited state of Ir(ppy)3 by benzonitrile 121 to generate radical anion 123 and Ir4+(ppy)3 (Scheme 28). Amine 122 is then oxidized to amine radical cation 124 by

• Ir4+(ppy)3 that is reduced to the initial catalyst, Ir(ppy)3. Deprotonation of amine radical cation 124 by NaOAc produces α-amino radical 125, which is coupled with radical anion 123 to form the key C–C bond in 126. Finally, aromatization via expulsion of the nitrile group provides benzylic amine 127

Synthesis of mucin-type O-glycan probes as aminopropyl glycosides

• David Benito-Alifonso,
• Rachel A. Jones,
• Anh-Tuan Tran,
• Hannah Woodward,
• Nichola Smith and
• M. Carmen Galan

Beilstein J. Org. Chem. 2013, 9, 1867–1872, doi:10.3762/bjoc.9.218

• groups using Ac2O and pyridine afforded the separation of the components and disaccharide 20b was then isolated with complete stereocontrol in 41% yield after the 3 steps. Adamantanyl thiosialosides have been shown to have high reactivity under NIS/TfOH promotion conditions in nitrile solvents at −35 °C

A practical synthesis of long-chain iso-fatty acids (iso-C₁₂–C₁₉) and related natural products

• Mark B. Richardson and
• Spencer J. Williams

Beilstein J. Org. Chem. 2013, 9, 1807–1812, doi:10.3762/bjoc.9.210

• . Alternatively, alcohol 12 could be intercepted and converted to the mesylate 13 using MsCl/Et3N [56] and thence the nitrile 14 (KCN in DMSO/THF). Finally, hydrolysis of the nitrile 14 with NaOH in H2O/EtOH afforded iso-C14 acid 3. The iso-C15–C17 fatty acids 4–6 were prepared from the readily available C15

• nitrile 27; and hydrolysis (NaOH in H2O/EtOH) of 27 afforded 8. The above routes enable the acquisition of (multi)gram quantities of the iso-C12–19 acids 1–8, and provide opportunities for their use as starting materials for the preparation of more complex fatty acids. To illustrate their potential we

[3 + 2]-Cycloadditions of nitrile ylides after photoactivation of vinyl azides under flow conditions

• Stephan Cludius-Brandt,
• Lukas Kupracz and
• Andreas Kirschning

Beilstein J. Org. Chem. 2013, 9, 1745–1750, doi:10.3762/bjoc.9.201

• with thermal formation of 2H-azirines. Photochemically, the ring of the 2H-azirines was opened to yield the nitrile ylides, which underwent a [3 + 2]-cycloaddition with 1,3-dipolarophiles. When diisopropyl azodicarboxylate serves as the dipolarophile, 1,3,4-triazoles become directly accessible starting

• from the corresponding vinyl azide. Keywords: azirines; cycloaddition; flow chemistry; flow reactors; inductive heating; nitrile ylides; photochemistry; vinyl azides; Introduction Recently, photochemistry has seen a renaissance despite the fact that under batch conditions specialized reaction vessels

• to perform many transformations that are hardly possible under thermal conditions. This includes photocatalytic reactions that have seen an immense interest lately [1]. Nitrile ylides 3 are 1,3-dipoles that have served for the preparation of different five-membered N-heterocycles in 1,3-dipolar

Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor

• Rajesh Munirathinam,
• Roberto Ricciardi,
• Richard J. M. Egberink,
• Jurriaan Huskens,
• Michael Holtkamp,
• Herbert Wormeester,
• Uwe Karst and
• Willem Verboom

Beilstein J. Org. Chem. 2013, 9, 1698–1704, doi:10.3762/bjoc.9.194

• °C was needed to give the nitrile 8 in 82% [18]. Anthracen-9-carbaldehyde oxime (5, Table 2, entry 3) showed a relatively poor conversion, which is ascribed to the steric hindrance of the molecule in reaching the catalytically active sites within the polymer brushes. In literature [18] this reaction

• , using gallium(III) triflate, required a reaction time of 8 h in refluxing acetonitrile to obtain the corresponding nitrile 10 in 87% yield. In case of 2-hydroxy-1-naphthaldehyde oxime (6) [22] (Table 2, entry 4) and salicylaldehyde oxime (7) [18] (Table 2, entry 5) dehydration happened between the ortho

• corresponding product 10 has a molar absorptivity (ε) of 13400 L·mol−1·cm−1 in that region. On-line UV–vis detection The conversion of the oximes was followed using online UV–vis spectrometry as described in reference [16]. Gallium-catalyzed formation of nitrile 2 at 90 °C and 5 atm pressure. Arrhenius plot for

The rapid generation of isothiocyanates in flow

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 1613–1619, doi:10.3762/bjoc.9.184

• chemical transformation which typically eliminates the requirements for any conventional work-up or purification of the reaction stream. Keywords: chloroxime; dipolar cycloaddition; flow chemistry; flow synthesis; immobilised reagents; isothiocyanate; nitrile oxide; Introduction Flow based chemical

• ], both reagents causing safety concerns due to the formation of toxic, malodorous and/or extremely corrosive byproducts (Scheme 1a). An underutilised alternative sequence is the 1,3-dipolar cycloaddition reaction between a nitrile oxide and a thiourea compound which initially generates an unstable 1,4,2

• -oxathiazoline intermediate that readily rearranges into urea and eliminates the desired isothiocyanate product [37][38] (Scheme 1b). Whilst this approach appears on initial inspection to be very attractive it is somewhat hampered by the requirement to access the reactive nitrile oxide species, which once formed

A Lewis acid-promoted Pinner reaction

• Dominik Pfaff,
• Gregor Nemecek and
• Joachim Podlech

Beilstein J. Org. Chem. 2013, 9, 1572–1577, doi:10.3762/bjoc.9.179

• identified as an imidate hydrochloride (Scheme 1). Best results in the Pinner reaction are obtained with primary or secondary alcohols and aliphatic or aromatic nitriles. A plausible mechanism (Scheme 2) starts with a protonation of the nitrile by the strong acid hydrogen chloride leading to a highly

• optimization we used the acylation of 9H-fluoren-9-ylmethanol (1) with acetonitrile as the nitrile component and solvent (Scheme 4). This substrate and the respective ester 2 are simply detected by thin-layer chromatography (TLC) and their molecular weights prevent losses during evaporation procedures. A 72

• % yield was achieved, when two equivalents of hafnium(IV) triflate were used and when the nitrile was used as the solvent (Table 1, entry 1). Catalytic amounts of this Lewis acid led to unsatisfactory yields, when the reaction was performed in acetonitrile or in mixtures of acetonitrile with water (Table

A reductive coupling strategy towards ripostatin A

• Kristin D. Schleicher and
• Timothy F. Jamison

Beilstein J. Org. Chem. 2013, 9, 1533–1550, doi:10.3762/bjoc.9.175

• synthesis [66]. The lithiated cyanohydrin acetonides react as nucleophiles with alkyl, allyl, and propargyl halides, as well as with epoxides. Although the alkylation itself is highly stereoselective in favor of the axial nitrile, the syn-1,3-diol stereochemistry is ultimately set in a subsequent reductive

• . To this end, reduction of the nitrile proceeded with the expected selectivity; this arises from equilibration of the intermediate radical to the more stable axial radical. It was essential to allow the reaction to warm under reflux due to the insolubility of the starting material in liquid ammonia

Simple synthesis of pyrrolo[3,2-e]indole-1-carbonitriles

• Adam Trawczyński,
• Robert Bujok,
• Zbigniew Wróbel and
• Krzysztof Wojciechowski

Beilstein J. Org. Chem. 2013, 9, 934–941, doi:10.3762/bjoc.9.107

• palladium-catalyzed hydrogenation of 5-nitroindol-4-ylacetonitriles 2 [6]. In the latter synthesis of pyrrolo[3,2-e]indole 3 the starting nitrile 2 was obtained by the vicarious nucleophilic substitution (VNS) [7][8][9][10][11] of hydrogen in 1-alkyl-5-nitroindole 1 with 4-chlorophenoxyacetonitrile [12

• hydrogen in 1-benzyloxymethyl-2-methyl-5-nitroindole with 4-chlorophenoxyacetonitrile according to our earlier elaborated method [12]. Alkylation of the nitrile 4 with ethyl bromoacetate in the presence of K2CO3 led to the expected cyanoester 5a in 68% yield, but the product contained some contaminants

Spectroscopic characterization of photoaccumulated radical anions: a litmus test to evaluate the efficiency of photoinduced electron transfer (PET) processes

• Maurizio Fagnoni,
• Stefano Protti,
• Davide Ravelli and
• Angelo Albini

Beilstein J. Org. Chem. 2013, 9, 800–808, doi:10.3762/bjoc.9.91

• and the full regeneration of the starting nitrile, as confirmed by chromatographic analysis. Exactly the same behavior was observed by using triethylamine (TEA) as the donor. It is noteworthy from the practical point of view that with OXA the TCB•− was formed at about the same rate also in a nitrogen

• cation to give Bu3Sn+ and Bu• is favored. The C-centered radical is not oxidized by TCB•− (see Figure 4) but couples with it, resulting in efficient ipso-substitution of the nitrile (Φ 0.40) [18]. Thus, only path b' alone leads to the accumulation of the radical anion. Conclusion The above experiments

4-Pyridylnitrene and 2-pyrazinylcarbene

• Curt Wentrup,
• Ales Reisinger and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 754–760, doi:10.3762/bjoc.9.85

• -diazacyclohepta-1,2,4,6-tetraene (20). Further photolysis causes ring opening to the ketenimine 27. Keywords: carbene–nitrene interconversion; diazepines; flash vacuum thermolysis; matrix photochemistry; nitrile ylides; reactive intermediates; Introduction The carbene–nitrene interconversion exemplified with

• nitrenes possessing a 1,3-relationship between a nitrene centre and a ring nitrogen atom and leads to nitrile ylides, such as 9 in the case of 3-pyridylnitrene (7), whereby the actual ring opening may take place in either the nitrene itself or the ring-expanded ketenimine 8 (Scheme 2) [6][7][8]. A 1,7-H

• shift finally converts the nitrile ylide 9 to the open-chain ketenimine 10 (Scheme 2). 3-Pyridylcarbene undergoes analogous Type I ylidic ring opening to an ethynylvinylnitrile imine [6]. Type II ring opening is diradicaloid and proceeds via an open-chain vinylnitrene or biradical 13 in nitrenes such as

3-Pyridylnitrene, 2- and 4-pyrimidinylcarbenes, 3-quinolylnitrenes, and 4-quinazolinylcarbenes. Interconversion, ring expansion to diazacycloheptatetraenes, ring opening to nitrile ylides, and ring contraction to cyanopyrroles and cyanoindoles

• Curt Wentrup,
• Nguyen Mong Lan,
• Adelheid Lukosch,
• Pawel Bednarek and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 743–753, doi:10.3762/bjoc.9.84

• either the nitrenes or the diazacycloheptatetraenes to nitrile ylides. Keywords: carbene-nitrene interconversion; diazepines; flash vacuum thermolysis; matrix photochemistry; nitrile ylides; reactive intermediates; Introduction A multitude of rearrangements of heterocyclic nitrenes have been described

• to the formation of glutacononitriles in low yields [12]. In contrast, 3-pyridylnitrene (10) undergoes a different type of ring opening to the observable nitrile ylide 11 and subsequently the ketenimine 12 (Scheme 3) [13]. Nitrile imines [14] and nitrile ylides [15][16] may have either allenic or

• the (s,Z)-nitrile ylide 11 lies 5 kcal/mol above the open shell singlet nitrene S1 10, i.e., the barrier is only 11 kcal/mol above the cyclic ketenimine 16. This is lower than the barrier for direct ring opening of the nitrene 10 itself (16 kcal/mol) (Scheme 4 and Figure 1) [13]. Thus, while both the

Some aspects of radical chemistry in the assembly of complex molecular architectures

• Béatrice Quiclet-Sire and
• Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

• (nitrile, ketones, esters, pyridines, tetrazoles, etc.) are particularly suitable. Benzyl radicals are not reactive enough towards unactivated alkenes; they tend to accumulate in the medium and ultimately dimerise. (b) The addition product, 30, being itself a xanthate, allows the implementation of a second

From bead to flask: Synthesis of a complex β-amido-amide for probe-development studies

• Kevin S. Martin,
• Cristian Soldi,
• Kellan N. Candee,
• Hiromi I. Wettersten,
• Robert H. Weiss and
• Jared T. Shaw

Beilstein J. Org. Chem. 2013, 9, 260–264, doi:10.3762/bjoc.9.31

• benzimidazole 3 with isocyanate 2 (Figure 2). We initially sought to avoid nitration, protection and deprotection steps and access this intermediate by performing a late-stage 3CR with benzimidazole 4, which would be available from nitrile 6 or acid 7 (Figure 2, A). Although synthesis of 4 proceeded without

• , B). Gratifyingly, 10 was converted to the requisite benzimidizole 3 in three steps and carried through to 1. Results and Discussion Our initial target was benzimidazole 4, which we envisioned originating from nitrile 6 or acid 7, each of which is commercially available (Figure 2). We first attempted

• to synthesize 4 from 6, which would lead to the shortest possible synthesis of 1. Nitrile 6 was treated with N-(3-aminopropyl)pyrrolidine (8) to produce aniline 12 in 81% yield (Scheme 1) [19]. This compound was reduced to aniline 13 in 79% yield and converted to the benzimidizole 14 in 63% yield

Metal–ligand multiple bonds as frustrated Lewis pairs for C–H functionalization

• Matthew T. Whited

Beilstein J. Org. Chem. 2012, 8, 1554–1563, doi:10.3762/bjoc.8.177

•  5) [38]. This reaction is important for the hydroamination of alkynes by Cp2ZrX2 complexes, which proceeds through zirconium imido intermediates [39]. A similar [2 + 2] cycloaddition of symmetrical alkynes across a tungsten nitride is the initial step in Johnson's nitrile-alkyne cross metathesis

• into a phosphine/borane FLP [14]. Oxygen-atom extrusion from CO2 by a Ta(V) neopentylidene [27]. Oxygen-atom transfer from acetone at a Zr(IV) imide [28]. Alkyne cycloaddition at a Zr(IV) imide [38]. Nitrile-alkyne cross metathesis at a W(VI) nitride [40][41]. C–H and H–H addition across a zirconium(IV

Aryl nitrile oxide cycloaddition reactions in the presence of pinacol boronic acid ester

• Sarah L. Harding,
• Sebastian M. Marcuccio and
• G. Paul Savage

Beilstein J. Org. Chem. 2012, 8, 606–612, doi:10.3762/bjoc.8.67

• dual functionality consisting of a nitrile oxide and a pinacolyl boronate ester was prepared by mild hypervalent iodine oxidation (diacetoxyiodobenzene) of the corresponding aldoxime, without decomposition of the boronate functionality. The nitrile oxide was trapped in situ with a variety of

• dipolarophiles to yield aryl isoxazolines with the boronate ester function intact and available for subsequent reaction. Keywords: dipolar cycloaddition; heterocycle; nitrile oxide; hypervalent iodine oxidation; pinacol boronic acid esters; Introduction Metal-mediated coupling reactions to form carbon–carbon

• convenient substrate would be the arylboronate nitrile oxide 1, which would undergo 1,3-dipolar cycloaddition to give isoxazolines 2. This latter compound could in turn be coupled with heterocycles or aryl groups to give insecticidal [5] derivatives of type 3 (Scheme 1). The utility of arylboronic acids and

Cyanoethylation of the glucans dextran and pullulan: Substitution pattern and formation of nanostructures and entrapment of magnetic nanoparticles

• Kathrin Fiege,
• Heinrich Lünsdorf,
• Sevil Atarijabarzadeh and
• Petra Mischnick

Beilstein J. Org. Chem. 2012, 8, 551–566, doi:10.3762/bjoc.8.63

• ) decreased, with the maximum being shifted to higher wavenumbers (→ less hydrogen bonding). No side products, such as amides or carboxylates (as hydrolysis products of nitrile groups), or only traces thereof, were observed [21]. ATR–IR spectra of native dextran and the cyanoethyl ethers are shown in Figure 2

• dextrans (in D2O) it is shifted from 4.97 to 5.16 ppm. The average DS value was calculated from the ratio of the signal integrals of the methylene group adjacent to the nitrile group, to the summarized integrals of H-1 (Equation 1). DS evaluation in position 2 is also possible (Equation 2). For

• the iron oxide core and obviously an interaction with the nitrile groups should be considered [45][47]. Entrapping of iron oxide cores during the carbohydrate nanostructuring process is proven by the electron micrographs. Figure 12 shows the net iron distribution, colored red, in the multicore

Syntheses and applications of furanyl-functionalised 2,2’:6’,2’’-terpyridines

• Jérôme Husson and
• Michael Knorr

Beilstein J. Org. Chem. 2012, 8, 379–389, doi:10.3762/bjoc.8.41

• ]. The synthetic pathway begins with the preparation of N,N′-dioxides 49 and 50 upon reaction with MCPBA. Treatment with trimethylsilyl cyanide allowed the introduction of a cyano group at the α-position with respect to the N-atoms, thus yielding the bis(nitrile) compounds 51 and 52. The cyano group was

Aldol elaboration of 4,5,6,7-tetrahydroisoxazolo[4,3-c]pyridin-4-ones, masked precursors to acylpyridones

• Raymond C. F. Jones,
• Abdul K. Choudhury,
• James N. Iley,
• Mark E. Light,
• Georgia Loizou and
• Terence A. Pillainayagam

Beilstein J. Org. Chem. 2012, 8, 308–312, doi:10.3762/bjoc.8.33

• genetic techniques, and been shown to involve conversion from an acyltetramic acid by oxidative ring expansion [7][8]. During a programme of synthesis towards metabolites containing the enolised heterocyclic tricarbonyl motif 3 [9][10][11][12][13][14][15][16], we have reported nitrile oxide dipolar

Synthesis of fused tricyclic amines unsubstituted at the ring-junction positions by a cascade condensation, cyclization, cycloaddition then decarbonylation strategy

• Iain Coldham,
• Adam J. M. Burrell,
• Hélène D. S. Guerrand,
• Luke Watson,
• Nathaniel G. Martin and
• Niall Oram

Beilstein J. Org. Chem. 2012, 8, 107–111, doi:10.3762/bjoc.8.11

• -carbon substituent, alpha to the aldehyde group, that could potentially be removed after the cascade cyclization–cycloaddition chemistry. Starting from nitrile 3, we prepared three different aldehydes, as shown in Scheme 2 and Scheme 3. Double deprotonation (of the alcohol and alpha to the nitrile) of

• -butyldimethylsilyl ethers gave 7a and 7b. DIBAL-H reduction of nitrile 7b (n = 2) gave aldehyde 8b. The same reduction of nitrile 7a gave a low yield of the desired aldehyde 8a; so, an alternative strategy to prepare the aldehyde with one less methylene group in the side-chain was studied (Scheme 3). Alkylation of

• Scheme 4. Unfortunately, we were not able to remove the nitrile substituent from the product 13a using lithium in ammonia [24], which instead converted the ethyl ester to its primary carboxylic amide, or using DIBAL-H, which gave a complex mixture of products. Heating aldehyde 8a with glycine gave